1. Field of the Invention
The present invention relates to an electronic still camera of the type recording picture data in a recording medium implemented as a memory card, and a memory card applicable to such a camera and using an EEPROM (Electrically Erasable Programmable Read Only Memory).
2. Description of the Prior Art
It is a common practice with an electronic still camera to record picture data representative of a picture and generated by a CCD (Charged Coupled Device) array or similar solid-state image pick-up device in a recording medium, e.g., a memory card. Since the amount of data representative of, among others, a picture is great, they are compressed by, for example, orthogonal transform coding and then written to a recording medium.
A memory card for use with the above-described type of electronic still camera has customarily been implemented by an SRAM (Static Random Access Memory) capable of writing and reading data at a high speed. The problem with an SRAM is that it is volatile and, therefore, needs a back-up battery. Moreover, an SRAM capable of recording a great amount of data, e.g., picture data is expensive, increasing the cost of the memory card.
In light of the above, a memory card using an EEPROM is now under investigation. An EEPROM is a semiconductor memory which is inexpensive and nonvolatile and, therefore, does not need a back-up battery. However, since the writing speed available with an EEPROM is lower than the writing speed of an SRAM, and EEPROM limits the speed at which an electronic still camera can operate in a continuous shoot mode.